C# 中如何判断线程是否结束

private bool StartThreads()
         {
           
             bool IfTimesEnd = false;  
            
             IfRunOver = false;
          
      
             Thread newThread = new Thread(new ThreadStart(ThreadProc));
             newThread.Start();             while (!IfRunOver)
             {                        
                
                 IfTimesEnd = newThread.IsAlive;
                 System.Windows.Forms.Application.DoEvents();
                 if (!IfTimesEnd || IfRunOver)
                 {
                     newThread.Interrupt();
                     newThread.Abort();
                     IfTimesEnd = false;
                     break;
                 }
             }
             return !IfTimesEnd;